Article: Multituberculate mammals from the Upper Jurassic Purbeck Limestone Formation of southern England
The multituberculate suborders: Paulchoffatoidea (Hahn, 1961, new rank) and Plagiaulacoidea (Simpson, 1925), plagiaulacoid families Plagiaulacidae (with two subfamilies Plagiaulacinae and Eobaatarinae) and Allodontidae are re-diagnosed. The Arginbaataridae is assigned to a suborder incertae sedis. It is demonstrated that Plioprion Cope, 1884, based on lower jaws, is a junior synonym of Bolodon Owen, 1871, based on upper jaws. A dentary fragment and twenty-five isolated multituberculate teeth from the Upper Jurassic Purbeck Limestone Formation are described. In one case seven teeth found in one sample are regarded as belonging to the same individual. Bolodon and Plagiaulax Falconer, 1857 are assigned to the Plagiaulacinae; the systematic position of Zofiabaatar Bakker and Carpenter, 1990 is uncertain: Ctenacodon Marsh, 1879 and Psalodon Simpson. 1926 are assigned to the Allodontidae. Two taxa are erected: Gerhardodon purbeckensis gen. et sp. nov. and Sunnyodon notleyi gen. et sp. nov., assigned to the Paulchoffatiidae. An upper premolar with three main cusps, additional cusps, cuspules and pits, is different from any hitherto known and is identified as ?Plagiaulacinae gen. et sp. indet. The new taxa are notably smaller than those previously known from the Purbeck Limestone Formation of England, probably the result of the screen-washing method employed in their collection.